How would a homeless person spend $100?

I would buy some food. Not with the entire amount as I could not store it hygienically, nor would I be able to carry it all.

$100 might mean lunch for you and a friend. For me it represents an entire month or more of meals, depending on how many times I wanted to eat per day. I could easily stretch it to 3 months or more.

I can walk into a supermarket and get a toothbrush for 15p. The local ASDA (owned by Walmart) sells tents for £12. Yes, they're crap, but a tent is a tent. A pound shop sells 3m X 3m tarpaulins for - surprisingly - £1. Walk into the camping/festival section and pick up a load of paracord for the same price. For the princely sum of £15 I've just created a campsite, with a groundsheet under the tent and a rainsheet rigged over the top. I am relatively warm, but very dry.

Charity shops are a good place to get warm clothes for next to nothing. They won't look good, but that didn't matter to me.

Off to a military surplus shop next. My local one sells sleeping bags for £10. They are often brand new, unused.

Back to the supermarket for a small bottle of water. They sSteel Aluminum Tents Manufacturersell “own brand” bottles for around 25p. I don't want it for the water (but it won't be wasted), I want the bottle itself. Once I've finished drinking the water it contains, I can easily refill it all over the place. Clean drinking water is easy to get in the UK as all water coming out of a tap must be legally safe to drink. Any public toilet with a sink and I can refill my bottle with clean, safe water.

You would think some means of cooking would be good at this point. Unfortunately gas costs a lot of money, so that option is out. Back to the military surplus shop for a bushcraft stove. It uses twigs in a small enclosed compartment to heat whatever is in the kettle above. It's safe and the fuel is free and can literally be found everywhere. That's another £25.

So far I have a tent, couple of tarpaulins to use as groundsheets and rain covers, sleeping bag, toothbrush, water bottle and a stove. I've got some warm clothing from a charity shop. I've got around £50 left for food, and if I ration myself to one small meal a day, I can easily make that last a month or slightly more.

But I can only do all that because I know what to do and where to go to get them. Hindsight is a wonderful thing.

When I was homeless I didn't know about any of those things. I'd only ever seen tents in camping shops, and they were expensive. Camping stoves used gas and I didn't know how to use them anyway. Only poor people ate own-brand food, and I wasn't one of them. I had never been into a militaryChina Steel Aluminum Tents Manufacturers surplus shop and thought that's where you went to buy guns and tell bullshit stories about that time you were in special forces in 'Nam. It had never occurred to me to think about how to store food. Sure, this goes into the fridge, that's for the freezer. Those go in the cupboards. But what if you don't have a fridge, or cupboards, or even a kitchen? I had no idea.

Nowadays, having lived that life, been homeless, and come out the other side almost 20 years ago, I could easily make $100 last me a very long time if I ever found myself on the streets again, and be relatively comfortable about it. But that’s only because I know what to do and where to go.

Now to answer the actual question. If I had been given $100 the day I became homeless, I would have spent it on food, an overpriced blanket and something warm to drink. I would have wasted that money in McDonald's over the next few days and had almost nothing to show for it in the end.

What I would do with it now, and what I would do back then are hugely different answers.